The effective range of device-to-device voice and data transmission is affected by many factors including transmit power, antenna characteristics, receiver sensitivity and system cost. Range limitations define the usable coverage area for radio communications with greater range generally equating to better user experience. As the range of a radio system decreases, so too does its usability, adoption, and commercial viability.
Present solutions to the problem of range limitations in wireless voice and data communications typically include increasing the transmit power, increasing the gain of the transmit and/or receive antenna, and leveraging low-noise architectures to increase receiver sensitivity. In mobile applications, increasing the gain of the antenna is not always possible due to form-factor constraints. As mobile applications are frequently power-constrained, increasing the transmit power results in perceptibly reduced battery life, to the detriment of device longevity and user experience. There are regulatory limits to the maximum allowable transmit power, so arbitrarily increasing the transmit power to achieve greater range is not considered a viable solution.
Present solutions optimize singularly for range, seeking to maximize the range without consideration for how functionality can be adapted to best suit varying operating conditions. This fails to recognize that multiple operating modes can be utilized to provide the best overall user experience. Accordingly, there is a need for improved technologies to support radio communication over extended ranges and poor conditions, consistent with battery and power constraints of portable devices, and without compromising performance in favorable or intermediate conditions.